Take a look at John Tavener's God is With Us and Holst's Christmas Day. Neither is explicitly written for ssa/satb double choir but both could be adapted very easily. I did the Tavener two years ago for Christmas Eve and our congregation is still talking about it.

I could not agree more with those who suggest Holst' Christmas day and Drake's arrangement of In the bleak midwinter. H. W. Gray once carried works by Clarence Dickinson. One of Dickinson's jewels was Jesu, thou dear babe divine. You would be remiss in not trying to locate a copy(ies) of this work. Why not perform George F. Strickling's SSA voicing of O Holy Night: Banks Music Pubications, #6495; order via website... http://www.banksmusicpublications.co.uk. Also, why not a processional on Willcock's O come, all ye faithful (Adeste fidelis): from Carols for Christmas, Volume I for SSAA and SATB, edited by R. Jacques, D. Willcocks, and J. Rutter, Oxford University Press, pub. # 9780193532229 or through Peppers (# 625681 or 7430028) or Jesu bambino by Yon: ALfred Pub., FEC04659 SATB (FECO4657 SSA) or at Peppers 102152 (SATB) and 102061 (SSA). Additionally, there is a newer work by Linda Spevicek Jesus, infant holy which, at the end, lends itself to Silent night and you could use some very interesting accompaniments with that carol. The data on Linda's work is Jesus, infant holy, Heritage Music, SA, # 15/3008H (Pepper's: 10366655). Finally, you would again be remiss if you did not include a work called Good-night and Christmas prayer by Foster. Although no longer published, you can locate it at http://www.musicaneo.com/sheetmusic/sm-82642_good-night_and_christmas_prayer.html.

If you would like it arranged for SSA or SATB, I suggest that the first half (Good-night) be a solo and the Prayer be choral. If you need assistance with arrangements of Good-night and Christmas prayer and/or Silent night, or O come all ye faithful (Adeste fidelis), I would be happy to assist. -John H. Briggs, Sr., MM (Jack)

I hope you'll take a look at my This Holy Christmas Night, for SATB and organ. This work was a past winner in the VocalEssence/American Composers Forum Welcome Christmas! Carol Contest. Published by Walton -- here's a link to information about it on my site:

It wasn't wholly clear whether you meant SATB + SSA w/org, or separate works with each of these voicings.

If the former:

I'd like to suggest my Images of Christmas (Fred Bock Music; special print order) which is for SA (unis-2 parts, though that could change...!) and SATB with organ and/or harp. You may listen to it on Soundcloud.com here:

Any of the following SATB settings, all published by Oxford University Press, would work well with just organ (or piano), although the recordings on soundcloud have orchestral accompaniment. Vocal scores are obtainable from OUP.

For SATB, William Mathias' A Babe Is Born, which is in Carols for Choirs 3 as well as 100 Carols for Choirs, and also as a separate octavo (all Oxford University Press/C.F.Peters). A little tricky in spots but very fun! Bill

There are the "Weinachts-Responsieren" of Johann Michael HAYDN for SATB, two violins and organ, in German. If you haven't got violin's, you can play only SATB with organ. The editor is CARUS. I conducted some of them two years ago and these pieces are charming and not too difficut to learn. I'll again conduct them at the Christmas evening in my church in Paris.

One of my all time favourite Christmas carol arrangements with a magnificent organ part is Kenneth Leighton's "O Leave Your Sheep" - marvellous setting, each verse very different, with a grand ending. Published by Novello.

There are the "Weinachts-Responsieren" of Johann Michael HAYDN for SATB, two violins and organ, in German. If you haven't got violin's, you can play only SATB with organ. The editor is CARUS. I conducted some of them two years ago and these pieces are charming and not too difficut to learn. I'll again conduct them at the Christmas evening in my church in Paris.